The first initial diagnosis of Ebola has landed on U.S. soil. A man who had flown recently from Liberia presented on September 26 at Texas Health Presbyterian Hospital with fever and malaise. He was treated with antibiotics and sent home. By September 28, Duncan was back in the hospital and placed in quarantine.
Texas public health officials say that up to 100 people may have been exposed. Ebola has a long incubation period and patients become highly contagious only late in the course of the disease. Both from my own perceptions of watching the disease since it was first diagnosed back in 1976, and from talking to professionals who were working with it and trying to develop a vaccine, I don’t believe that Ebola, along with a whole list of horrible hemorrhagic fevers caused by a spectrum of different viruses (Junin, Korean Hemorrhagic Fever, Sin Nombre), constitutes a substantial pandemic risk. With all the federal and state resources available, along with the fact that the Liberian community in Dallas will be both readily contacted and sophisticated in how they handle information, the worst case scenario is a very limited, and likely local, outbreak.
But there are still no vaccines nor drugs nor cure for Ebola.
Gary Nabel’s group at the NIH Vaccine Research Center has been publishing on experimental Ebola vaccines for years, with 2010 seeing an account of what looks to be a reasonable candidate. Why isn’t that, or something similar, available now? The answer is one word: money. Developing and testing any product for human use runs in the range of hundreds of thousands to a billion dollars. We can’t expect industry to go down this road for vaccines with a minimal market. In addition, the Ebola outbreak is happening in West Africa, where substantial numbers of people die each year from yellow fever. We’ve had a yellow fever vaccine for more than half a century, but the problem is affordability.
Currently, two candidate Ebola vaccines (including the NIH product) are being fast-tracked through human limited human trials, providing, perhaps, a model for the future. No doubt this will be used at the earliest possible date to protect health professionals but, once the current outbreak is over, it will be interesting to see who gets the vaccine for the future.
Financial constraints also apply when it comes to developing specific antiviral drugs (small molecules) to treat Ebola. Unlike antibiotics, antivirals need to be specific for the particular pathogen. There are good “designer drug” protocols for finding a virus’s “point of vulnerability” and making an appropriate chemical to block the infection. Think of the spectrum of such pills that keep HIV-infected people alive and well. Then there is the recent drug for treating Hepatitis C virus carriers, which retails for about $80,000 per treatment.
Again, where will the money come from to bring such a product to market for a sporadic, developing-world disease like Ebola? Mimicking our own antibody response to infection, there was some evidence of clinical success with an Ebola-specific monoclonal antibody (mAb) made in genetically engineered tobacco. While many cancer patients, in particular, have been treated successfully and safely with mAbs, such “biologicals” are enormously expensive to make in sufficient volume for widespread use.
So what’s the bottom line? We could have been better prepared for his horrible Ebola epidemic, but who pays? The Bill and Melinda Gates Foundation has done a terrific job when it comes to countering developing world diseases, but they can’t do everything. One thing that would be inexpensive is to develop and distribute much better educational material using, for example, the cell phones that are as ubiquitous in developing countries as they are here.
And are we in for a U.S. Ebola epidemic, or even a pandemic? I don’t think so, though we should take this as a warning and exercise “duty of care” when it comes to sustaining our public health services.
Peter C. Doherty shared the 1996 Nobel Prize for Physiology or Medicine. He has worked on aspects of infection and immunity for almost 50 years. His recent books include Pandemics: What Everyone Needs to Know and Their Fate is Our Fate: How Birds Foretell Threats to Our Health and Our World. He spends his professional time between St. Jude Children’s Research Hospital, Memphis, and the University of Melbourne, Australia.